/**
 * Copyright (c) 2022 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <locale.h>
#include <string.h>
#include <sys/mman.h>
#include <stdlib.h>
#include "locale_impl.h"
#include "libc.h"
#include "lock.h"
#include "fork_impl.h"

#define malloc __libc_malloc
#define calloc undef
#define realloc undef
#define free undef

const char *__lctrans_impl(const char *msg, const struct __locale_map *lm)
{
    const char *trans = 0;
    if (lm) trans = __mo_lookup(lm->map, lm->map_size, msg);
    return trans ? trans : msg;
}

static const char envvars[][18] = {
    "LC_CTYPE",
    "LC_NUMERIC",
    "LC_TIME",
    "LC_COLLATE",
    "LC_MONETARY",
    "LC_MESSAGES",
    "LC_PAPER",
    "LC_NAME",
    "LC_ADDRESS",
    "LC_TELEPHONE",
    "LC_MEASUREMENT",
    "LC_IDENTIFICATION",
};

volatile int __locale_lock[1];
volatile int *const __locale_lockptr = __locale_lock;

const struct __locale_map *__get_locale(int cat, const char *val)
{
    static void *volatile loc_head;
    const struct __locale_map *p;
    struct __locale_map *new = 0;
    const char *path = 0, *z;
    char buf[256];
    size_t l, n;
    if (!*val) {
        (val = getenv("LC_ALL")) && *val ||
        (val = getenv(envvars[cat])) && *val ||
        (val = getenv("LANG")) && *val ||
        (val = "C.UTF-8");
    }

    /* Limit name length and forbid leading dot or any slashes. */
    for (n=0; n<LOCALE_NAME_MAX && val[n] && val[n]!='/'; n++);
    if (val[0]=='.' || val[n]) {
        val = "C.UTF-8";
    }
    int builtin = (val[0]=='C' && !val[1])
        || !strcmp(val, "C.UTF-8")
        || !strcmp(val, "POSIX");

    if (builtin) {
        if (cat == LC_CTYPE && val[1]=='.')
            return (void *)&__c_dot_utf8;
        return 0;
    }

    for (p=loc_head; p; p=p->next) {
        if (!strcmp(val, p->name)) {
            return p;
        }
    }

    if (!libc.secure) {
        path = getenv("MUSL_LOCPATH");
    }

    if (path) {
        for (; *path; path=z+!!*z) {
            z = __strchrnul(path, ':');
            l = z - path;
            if (l >= sizeof buf - n - 2) {
                continue;
            }
            memcpy(buf, path, l);
            buf[l] = '/';
            memcpy(buf+l+1, val, n);
            buf[l+1+n] = 0;
            size_t map_size;
            const void *map = __map_file(buf, &map_size);
            if (map) {
                new = malloc(sizeof *new);
                if (!new) {
                    __munmap((void *)map, map_size);
                    break;
                }
                new->map = map;
                new->map_size = map_size;
                memcpy(new->name, val, n);
                new->name[n] = 0;
                new->next = loc_head;
                loc_head = new;
                break;
            }
        }
    }

    /* If no locale definition was found, make a locale map
     * object anyway to store the name, which is kept for the
     * sake of being able to do message translations at the
     * application level. */
    if (!new && (new = malloc(sizeof *new))) {
        new->map = __c_dot_utf8.map;
        new->map_size = __c_dot_utf8.map_size;
        memcpy(new->name, val, n);
        new->name[n] = 0;
        new->next = loc_head;
        loc_head = new;
    }

    /* For LC_CTYPE, never return a null pointer unless the
     * requested name was "C" or "POSIX". */
    if (!new && cat == LC_CTYPE) new = (void *)&__c_dot_utf8;

    return new;
}
